1. Field of the Invention
The present invention relates to an apparatus and method for anchoring surgical suture to bone. More specifically, the present invention relates to arthroscopic apparatus and methods for anchoring suture to bone using a suture anchor having suture molded directly into the body of the suture anchor.
2. Description of the Related Art
When soft tissue tears away from bone, reattachment becomes necessary. Various fixation devices, including sutures, screws, staples, wedges, and plugs have been used in the past to secure soft tissue to bone. More recently, various types of threaded suture anchors have been developed.
Suture anchors and implants generally include a structure for attaching or securing the suture to the anchor. U.S. Pat. No. 4,632,100, for example, discloses and claims a threaded suture anchor with a complex press-fitted disc and knot structure which secures the suture to the anchor. In other suture anchors, such as those disclosed in U.S. Pat. No. 5,370,662, the suture is attached to the anchor by passing the suture through an eyelet at the back end of the anchor. Problems can arise if the structure for attaching the suture fails, allowing the suture to become detached from the anchor. Also, in some of the known devices, the suture is exposed to abrasion or cutting by sharp or rough areas along the walls of the bone canal into which the anchor is inserted.
In addition, the eyelet or, in the case of U.S. Pat. No. 4,632,100, the axial opening for receiving the disc to which the suture is knotted, is formed as part of the drive head of the known suture anchors, which weakens the drive head. Various other modifications in the drive head are often employed in connection with suture attachment. For example, recessed grooves may be formed on opposite sides of the drive head to receive and protect the suture from the abrasive areas of the suture anchor tunnel. In such cases, the drive head often is made of a larger diameter to recover the mechanical strength lost from the removal of material relating to the suture-attachment or suture-protection modification.
Accordingly, a need exists for a suture anchor or implant to which suture is secured effectively so as to prevent detachment of the suture. A need also exists for a soft tissue fixation device having a low profile configuration particularly suited for reattachment of tissue to the glenoid rim, for example.